Pollard B J, van der Spek A F
Department of Physiological Sciences, University of Manchester.
Br J Anaesth. 1988 Oct;61(4):419-24. doi: 10.1093/bja/61.4.419.
The action of hexamethonium has been investigated in the rat phrenic nerve-hemidiaphragm preparation, alone and in combination with the neuromuscular blocking agents tubocurarine, pancuronium and alcuronium. Hexamethonium alone in concentrations between 3.55 x 10(-3) and 7.1 x 10(-3) mol litre-1 produced neuromuscular blockade in a dose-dependent manner. Low concentrations of hexamethonium antagonized the neuromuscular blocking effect of all three neuromuscular blocking drugs, less with tubocurarine than with the other two. Increasing the concentration of hexamethonium produced potentiation of the neuromuscular blocking effect, this being greater with tubocurarine than with either pancuronium or alcuronium. The cholinesterase activity in rat diaphragm homogenates was inhibited by hexamethonium. This inhibition was only significant at concentrations greater than those which resulted in antagonism and cannot, therefore, explain the observed antagonism. The mechanism of these observations is discussed with respect to the known behaviour of a combination of antagonists acting within a receptor system.
已在大鼠膈神经 - 半膈肌标本中研究了六甲铵的作用，分别单独以及与神经肌肉阻滞剂筒箭毒碱、泮库溴铵和阿库氯铵联合使用时的作用。单独使用浓度在3.55×10⁻³至7.1×10⁻³摩尔/升之间的六甲铵以剂量依赖性方式产生神经肌肉阻滞。低浓度的六甲铵拮抗了所有三种神经肌肉阻滞药物的神经肌肉阻滞作用，对筒箭毒碱的拮抗作用比对其他两种药物的拮抗作用小。增加六甲铵的浓度会增强神经肌肉阻滞作用，对筒箭毒碱的增强作用比对泮库溴铵或阿库氯铵的增强作用更大。六甲铵抑制大鼠膈肌匀浆中的胆碱酯酶活性。这种抑制作用仅在高于导致拮抗作用的浓度时才显著，因此不能解释所观察到的拮抗作用。根据已知在受体系统内起作用的拮抗剂组合的行为对这些观察结果的机制进行了讨论。
